This invention is directed generally to a system for detecting and ejecting a disoriented or dissimilar object from a series of moving, otherwise similar or oriented objects. More particularly, the invention is directed to the problem of removing a reversely oriented member from a linearly arranged group or stack of otherwise identical and like-oriented members.
The detection and removal of dissimilar or irregular objects from moving lines, stacks or groups of otherwise similar or regularly formed objects is often encountered in automated production and handling lines. While the present invention may find utility in a broad variety of applications, the description will be facilitated by particular reference to the problem of detecting and ejecting a reversely oriented can end from a moving stack of otherwise like-oriented, nested can ends.
Automated production facilities generally handle but two basic parts in the assembly of cans or similar cylindrical containers. These parts comprise a cylindrical or tubular body which may have either one or both ends thereof open, and a closure member for the open end or ends. In this regard, the body may be formed by a process such as rolling and seaming of a generally flat strip of material to form a generally cylindrical, tubular body having both ends open. Alternatively, extruding or similar forming procedures may be utilized for forming a one-piece, seamless can or container body having but a single, generally circular, open end. In either case, a generally circular end closure member must be provided for each open end of each container to be fabricated or assembled. Normally the last such end assembled with the container is assembled therewith following the filling process.
It is common practice in automated assembly facilities to utilized preformed and prestacked can ends. In this regard, the can end utilized comprises a generally flat, circular member which has been preformed by suitable means to define peripherally projecting flange portions suitably shaped for mating with the outermost edge portions of the cylindrical container bodies. These flange portions, together with the central, body portion (which may be flat or crowned and also may have a "flip-top" type of opening assembly preformed and/or preassembled therewith) may be stacked together in a nested configuration.
In accordance with conventional practice, these nested stacks of can ends are usually provided in prepackaged form. That is, a given number, usually a multiple of 6, such as 300 or 360 can ends are prestacked in nested configuration and disposed in a paper bag or some other stripable or otherwise readily removable packaging material. Preferably, the entire package is introduced into a generally tubular conveyor or conduit member and thereupon the paper or other packaging material is automatically or manually removed in an axially rearward direction and the can ends are then fed to a processing machine wherein they are assembled to the can bodies. Automatic feeding of the ends is also used at the apparatus wherein a linear material is applied to the inner rim of the end.
It will be appreciated that such stripping and removal of the paper packaging material in an axial direction tends to impart a degree of frictional force to the can ends in the stack. This force is ordinarily of little consequence to the can ends interiorly or of the stack. However, with respect to those can ends at or near the end of the stack such frictional force may result in dislodgement or "flipping" of one or more of these can ends such that one or more of these dislodged can ends now lies in reverse orientation with respect to the remaining ends in the stack and is no longer nested.
In this latter regard, the configuration of the above-mentioned rims and generally crowned (if any) surfaces of the can ends is not a symmetrical configuration viewed from both sides thereof. Hence, an end placed in reverse orientation is no longer properly oriented and can not be accommodated by the processing equipment, and may lead to a malfunction of said equipment. Accordingly, it is desirable to detect such reversed can ends and eject them from the moving stack or line of can ends in the supply conduit prior to the point of introduction into the processing equipment for assemblying the ends with the container bodies.
Heretofore, such improperly or reversely oriented ends have generally been manually rejected, often together with the container body to which the automated machinery has attempted to assemble the improperly oriented end. This results in production delays, as well as considerable scrap both of which are costly.